Hiya.
I bought Freeworld3D a year or two ago. Bottom line...great landscaping tool, but pretty much useless unless you know how to program XML in order to write your own exporter. You *can* use it to export greyscale images for creating a .hmp in MED, however.
The guy who wrote it is finishing (as I remember it) his Doctorate in something or other...so he doesn't have time to work on it. I'm sure that once he does get his Dr., it will get a serious upgrade.

Now, I use GROME II. It is *very* powerful, and even has a beta version of a Game Studio exporter.